Eye Diseases: Main Groups of Diseases and Their Signs

Eye diseases are organic and functional lesions of the visual analyzer, that is, of the entire system that allows a person to see, as well as lesions of the adnexal apparatus of the eye: eyelids, lacrimal ducts, conjunctiva. According to the World Health Organization, at least two billion two hundred million people today live with near or distance vision impairment, and for almost half of them vision loss could have been prevented or has not yet received care. Understanding the general groups of diseases is useful for anyone who wants to notice something wrong in time and see a doctor.

What types of eye diseases exist

According to the International Classification of Diseases, eleven groups of eye diseases are distinguished. Refractive errors are conditions in which the eye does not focus the image accurately and the person sees poorly near or far. Cataract is clouding of the transparent lens, the natural lens inside the eye. Glaucoma is a group of conditions in which the pressure of fluid inside the eye gradually increases and the optic nerve is affected. Retinal diseases are lesions of the nerve layer deep in the eye, including age-related macular degeneration, in which sharp central vision is destroyed. Diabetic eye lesions, conjunctivitis — inflammation of the mucous membrane — and eyelid diseases such as blepharitis are distinguished separately. According to the World Health Organization, the leading causes of vision impairment and blindness in the world are refractive errors and cataract.

Diseases of the anterior segment of the eye and eyelids

The anterior segment includes the eyelids, conjunctiva, cornea, and lacrimal ducts. Conjunctivitis manifests as redness and itching of the eyes, and some of its forms are easily transmitted from person to person. Blepharitis — inflammation of the eyelid margins — and dry eye do not lead to blindness but cause noticeable discomfort and pain and often become a reason for seeing an ophthalmologist.

Diseases of the lens, retina, and optic nerve

These diseases are insidious in that they may not cause noticeable sensations for a long time. Cataract is more common with age and gradually reduces vision. Glaucoma usually develops due to a slow increase in the pressure of fluid inside the eye and, without medical monitoring, leads to irreversible vision loss. Age-related macular degeneration destroys central, sharpest vision. Diabetic eye lesions require especially early detection: with them, timely treatment is critical to avoid irreversible vision loss.

Eye diseases in children

In children the picture is different. In low-income countries, congenital cataract is named the leading cause of vision impairment; in middle-income countries, retinopathy of prematurity, a retinal lesion in children born early. In any country of the world, one common cause remains in children and adults — uncorrected refractive error. Early vision impairment in a small child can delay the development of movement, speech, emotions, and thinking, so children's vision should be checked regularly.

Which signs are considered alarming

Some eye diseases proceed without any symptoms, and that is precisely why regular examinations are so important. If the following signs appear, however, one should see an ophthalmologist without delay: the earlier monitoring begins, the greater the chance of slowing or preventing vision loss.

• Sudden change in vision.
• Everything around seems dim.
• Flashes of light before the eye.
• Eye pain, double vision.
• Swelling, redness, discharge from the eye.

An eye disease in itself is not a reason to call an ambulance; 103/112 — for a life-threatening condition, for example signs of stroke or severe injury. With a sudden change in vision, flashes of light, eye pain, or double vision, one should urgently see an ophthalmologist.

How an ophthalmologist detects eye diseases

The main method is a complete examination with pupil dilation using special drops: this way the doctor sees the retina and optic nerve and can notice a disease at an early stage. Visual acuity is checked using charts. Risk is assessed separately: it is higher with age, with excess body weight, with a family history of eye diseases, diabetes, and high blood pressure. Based on the results, the doctor decides which further examinations are needed.

This material is for reference and does not replace a doctor's consultation: only an ophthalmologist after an examination can say what is happening with your eyes.

This content is for reference and does not replace a doctor's consultation. Medical disclaimer